Pneumatically operated switch



A. BIZZARRI Nov. 28, 1933.

PNEUMATI CALLY OPERATED SWITCH Filed July 28, 1931 3 Sheets-Sheet l fi 5 Q III! I N V EN TOR. 4/vfi/0/W 6722A RR/ BY A TTORNEY 1933- A. BIZZARRI PNEUMATICALLY OPERATED SWITCH Filed July 28, 1931 3 Sheets-Sheet 2 mm Iv mm G. m NW w I T v w $1M K x Q R v. w 6 47. y g? M I m A. N v m 1 f. .iIziI Nm. I mm mm m Ms w mm m M ww & Q k $1 MN NB Q v w N. W N flaw m NW #TQN a WW N w 0 GN 3 NM MN .QQATTORNEY A. BIZZARRI Nov. 28, 1933.

PNEUMATI CALLY OPERATED SWI TCH Filed July 28, 1931 3 Sheets-Sheet 3 Patented Nov. 28, 1933 UNITED STATES PATENT OFFICE 3 Claims.

My present invention relates to pneumatically controlled switches and the like and aims to devise devices of the general character specified which are simple in construction, easy and economical to fabricate and assemble, and which are admirably adapted to perform the functions hereinafter referred to more in detail.

In the accompanying specification I shall describe, and in the annexed drawings show, an illustrative embodiment of the pneumatically controlled switches of the present invention. However, it is to be understood that I do not wish to be limited to the exact details shown and described herein for purposes of illustration only.

In the accompanying drawings:

Fig. 1 is a partially side elevational, partially longitudinal sectional, diagrammatic view of the aforesaid illustrative embodiment of the present invention in an operative position;

Fig. 2 is a similar view of the same in an intermediate position; and

Fig. 3 is a like view of the same in an inoperative position.

Referring now more in detail to the aforesaid illustrative embodiment of the pneumatically controlled switches of the present invention, and

with particular reference to the drawings illustrating the same,the numeral generally designates a casing having a vertical cylinder 11 sealed at the top thereof by a cap 12. Threadedly engaged in the cap 12 is a set screw 13 cooperable with a spring retainer 14 urging against an expansion spring 15 which, in turn, urges against a piston 16 operable in the cylinder 11, the arrangement being such as to permit the setting of the pressure at which the piston will operate for a purpose later to be described.

Formed with the piston 16 is a tubular extension, having a passage'lfi', the extension carrying at the end thereof a mushroom valve 17 and the passage cor'nmunicating'by way of a port 18 with a chamber 19 formed in the casing.

Carried onthe extension of the piston 16 is a floating combined valve and seat 20 retained in engagement with a stationary seat 21 formed in the. cylinder 11 by an expansion spring 22, a portion of the extension and the combined valve and seat being surrounded by a piece of rubber tubing 23 to prevent leakage. The cylinder 11 is completed by an inlet 24 and an outlet 25.

'The chamber 19 communicates with a horizontal cylinder 26 in which operates a piston 27 against one side of which urges an expansion spring 28 having its opposite end abutting a head or block 29, partially closing the cylinder 26.

Formed with the piston 2'7 is a tubular extension having a passage 30 and carried by the end of the extension is a mushroom valve 31, the passage 30 communicating by way of a port 32 with another chamber 33 formed in the casing 10.

Slidable on the extension of the piston 2'? is a floating combined valve and seat 34 retained in engagement with a stationary seat 35 formed in the cylinder 26 by an expansion spring 36, a portion of the extension and the combined 65 valve and seat being surrounded by a piece of rubber tubing 3'7 to prevent leakage.

Formed with the piston 2'7 and slidable in the head 29 is a rod 38 carrying at the end thereof a valve 39 cooperable with the seat 40 formed 70 with the head, the latter having a port 41 communicating intermediate the air chamber 42 thereof and the cylinder 26. The cylinder 26 is completed by an outlet i8 and the head 29 is completed by a cap 44 having an inlet 45.

The chamber 33 communicates with another horizontal cylinder 46 in which operates a piston 47 normally retained adjacent the chamber 33 by an expansion spring 48, one end of which abuts the piston and the other end of which abuts the main casing portion 49 of an electrical switch 50, or any other device, the operation of which it is desired to control by the devices of the present invention.

Formed with the piston 47 and reciprocatable in the casing 49 is a toggle spring sleeve 51 having the conical wall 52 and the cylindrical end portion 53 which is intended to receive the reciprocatable plunger subsequently referred to. The toggle sleeve 51 is provided with bearing portions 54 to provide fixed bearings for the toggle springs, also subsequently referred to.

I now provide suitable means so arranged that when the sleeve 51 is moved, the means becomes increasingly compressed until a central or dead center position is reached, out of which such means will be snapped beyond the dead center to quickly open or close the switch, the details of which will be later described. I prefer to use a plurality of cooperating split circular or ring springs 55 and 56. Each of the springs has a bearing along one portion thereof in contact with the bearing surfaces 54 of the sleeve 51. It may here be stated that the effective external diameter of each of the springs when in a normal or uncompressed condition is preferably greater than half of the diameter of the interior of the sleeve 51.

The'springs 55 and 56 are secured in a reciprocatable plunger 57 operable in the end portion 53 of the sleeve 51. For this purpose, the plunger 57 has an enlarged portion 58 slotted at 59 to receive the interior portions of the springs. It will thus be noted that the springs are oppositely disposed and are obliquely arranged with respect to the axis of the plunger 57 when the switch is in either an open or closed position, the springs being aligned and thus normal to the axis of the plunger only when the same are subjected to maximum compression along a dead center in the intermediate position of the springs.

Carried by the enlarged portion 58 of the plunger 57 is a bridging contact 59, adapted to engage, when the switch is closed, the two contacts 60 and 61 supported by an insulating portion 62 of the switch. A stop 63 limits the movement of the bridging contact 59 in its movement away from the contacts 60 and 61.

The switch 50 is intended to control the flow of current to an electrical motor 64 which drives an air compressor or pump 65. The latter has an air inlet 66 and an air outlet 67 provided with a valve 68, the outlet being connected by a pipe 69 with an expansion chamber 70. The expansion chamber is connected by a pipe 71 with the inlet 45 of the cylinder 26 and by another pipe 72 containing a check valve '73 with a tank or reservoir 74 for air under pressure. The tank, in turn, is connected by a pipe 75 with the inlet 24 of the cylinder 11 and is provided with an outlet 76 to which may be connected a hose or any other means to convey the air stored in the tank to the place where it is to be used. The contact 60 is connected by a wire 77 to a source of electrical current (not shown) and the contact 61 is connected by a wire 78 to one terminal of the motor 64, the other terminal of the motor being connected by a wire 79 to the remaining end of the source of electric current.

This completes the description of the aforesaid illustrative embodiment of the pneumatically controlled switches of the present invention, and while the mode of operation and use thereof is believed to be clearly apparent from the foregoing description, the same may be briefly summarized as follows:

With the various parts of the device in the position shown in Fig. 1 of the drawings, the bridging contact 59 is in engagement with the contacts 60 and 61 so that the electrical circuit through the motor 64 is closed. Thus, the com pressor or pump is in operation and the reservoir 74 is being filled with air under pressure. Let us assume that the set screw 13 has been adjusted so that the devicewill function as soon as the pressure in the reservoir '74 reaches two hundred pounds. It will be noted that as the air leaves the outlet 67 of the compressor 65, it passes the valve 68, through the pipe 69, and into the expansion chamber '70. From this point, the air passes the check valve 73 into the tank 74. It also passes through the pipe 71 to the air chamber 42 of the head 29 of the cylinder 26. As will be readily understood by those skilled in the art to which the present invention relates, a certain amount of moisture will be collected in the expansion chamber when the air is pumped therethrough. From the tank 74 the air may be withdrawn through the outlet 76 and through any hose or other conveying means that may be attached thereto, so that the same can be used. It will also be noted that air from the tank 74 passes through the pipe into the cylinder 11.

As soon as the pressure in the tank 74 and thus the cylinder 11 becomes greater than two hundred pounds, which is the maximum pressure to which the device has been set by the adjustment of the set screw 13, the piston 16 will be moved in the cylinder 11 against the action of the spring 15. This will cause the mushroom valve 17 to close against the combined valve and seat 20, thus sealing the communication between the port 16 and the chamber 19. Continued movement of the piston 16 causes the combined valve and seat 20 to move away from the stationary seat 21. This permits the air in the cylinder 11 to pass into the chamber 19 and from there into the cylinder 26. The air that is now in the cylinder 26 will move the piston 27 against the action of the spring 28 so as to unseat the valve 39. As a result, the air in the expansion chamber 70 and the air chamber 42 of the head 29, together with the moisture collected in the expansion chamber 70, will pass through the port 41 into the cylinder 26 and from there out to the atmosphere by way of the port 43. This relieves the load from the motor 64 and permits the more easy control thereof.

As the piston 27 continues to move against the action of the spring 28, the mushroom valve 31 engages the combined valve and seat 34, thus sealing the communication between the port 30 and the air chamber 33. The still further movement of the pistion 27 causes the combined valve and seat 34 to be moved away from the stationary seat 35, thus permitting the air in the cylinder 26 to pass through the chamber 33 and into the cylinder 46. The air that is now in the cylinder 46 urges the piston 47 against the action of the spring 48. This movement is, of course, transmitted to the toggle sleeve 51 so that the springs 55 and 56 will be compressed increasingly until they are aligned and normal to the axis of the plunger 57. As soon as the springs pass the dead center, they will become uncompressed with a snap action, causing the plunger 57 to ride within the end portion 53 of the sleeve 51 and at the same time quickly remove the bridging contact 59' from engagement with the contacts 60 and 61. This will break the electrical circuit through the motor 64, thus stopping the operation of the compressor 65, forcing no more air into the reservoir 74. Thus the reservoir 74 will now be filled with air up to the maximum pressure.

As the air is withdrawn from the reservoir 74, as by using the same for filling automobile tires or any other pneumatic appliances, the pressure in the reservoir and, in fact, throughout the entire system, will become reduced.

As soon as the strength of the spring 15 is sufiicient to overcome the pressure of the air in the cylinder 11, the piston 16 will begin to return to its normal position. The first result 01' this movement of the piston 16 will be to close the combined valve and seat 20 against the seat 21, thus sealing the communication between the cylinder 11 and the air chamber 19. Continued movement of the piston 16 toward its normal position will crack the valve 17, thus permitting the air in the cylinder 26 and the air chamber 19 to pass through the port 18, through the passage 16' and out of the cylinder 11 by way of the port 25 leading to the atmosphere. As the pressure in the cylinder 26 is reduced, the spring 28 will start to move the piston 27 toward its normal position. The first result of this movement will be to engage the combined valve and seat 34 with the seat 35, thus sealing the communication between the cylinder 26 and the chamber 33 and cylinder 46. Continued movement of the @ton 27 toward its normal position will crack the valve 31, thus permitting the air in the cylinder 46 and air chamber 33 to pass through the port 32, passage 30, out of the cylinder 26 by way of the port 43 leading to the atmosphere. The stillfurther movement of the piston 27 toward its normal position will close the valve 39 against its seat 40, thus preventing any further air from the expansion chamber '70 and. air chamber 42 of the head 29 to escape through the ports 41 and 43. As the pressure in the cylinder 46 decreases, the spring 48 will start to return the piston 47 toward its normal position adjacent the air chamber 33. This movement will, of course, be transmitted to the toggle sleeve 51 so that the springs 55 and 56 will be operated in the reverse direction to that described above. As soon as the springs pass the dead center position, they will become uncompressed with a snap action, thus quickly bringing about the engagement between the bridging contact 59 and the contacts 60 and 61. This will close the electrical circuit through the motor 64 and the compressor 65 will again be operated to repeat the cycle of operations just described.

This completes the description of the mode of operation and use of the aforesaid illustrative embodiment of the pneumatically controlled switches of the present invention. It is to be understood that I do not wish to be limited to the use of the control devices of the present invention in connection with electrical switches. The movement of the piston 47 may be utilized to control many other devices, not necessarily electrical switches.

t will be noted from the foregoing description that the devices of the present invention are simple in construction, easy and economical to fabricate, and admirably adapted to perform the functions set forth in earlier portions of this specification. Other superiorities and advantages of the devices of the present invention will be obvious to those skilled in the art to which the present invention relates.

What I claim as my invention is:

1. Apparatus to control filling means for filling fiuid reservoirs, comprising a casing having a plurality of cylinders, cooperating pressure-actuated pistons operable in said cylinders and a pair of cooperating valves associated with each of said pistons, said cylinders, pistons and valves constituting means for operating the filling means when the pressure in the reservoir reaches a predetermined minimum and stopping the operation of the filling means when the pressure in the reservoir reaches a predetermined maximum.

2. Apparatus to control filling means for filling fluid reservoirs, comprising a switch and means to open and close the same with a snap action, a casing having a plurality of cylinders, cooperating pressure-actuated pistons operable in said cylinders and a pair of cooperating valves associated with each of said pistons, said cylinders, pistons and valves constituting means to actuate said switch for operating the filling means when the pressure in the reservoir reaches a predetermined minimum and stopping the operation of the filling means when the pressure in the reservoir reaches a predetermined maximum.

3. Apparatus to control filling means for filling fluid reservoirs, comprising a switch and a pair of cooperating split ring springs to open and close the same with a snap action, a casing having a plurality of cylinders, cooperating pressure-actuated pistons operable in said cylinders and a pair of cooperating valves associated with each of said pistons, said cylinders, pistons and valves constituting means to actuate said switch for operating the filling means when the pressure in the reservoir reaches a predetermined minimum and stopping the operation of the filling means when the pressure in the reservoir reaches a predetermined maximum.

ANTHONY BIZZARRI. 

